Updated October 17, 2026. Quick answer: Line 5 is the social security and Medicare tax on tips you did not report to your employer, and it comes from Form 4137. Line 6 is the uncollected social security and Medicare tax on wages, and it comes from Form 8919. Line 7 adds lines 5 and 6.
Schedule 8812 (child tax credit and additional child tax credit) for 2025, read line by line: Schedule 8812 lines 21 to 26.
Line 5: tax on unreported tips
The form’s caption for line 5 reads “Social security and Medicare tax on unreported tip income. Attach Form 4137”. The instructions say what to enter: “Enter the total of any taxes from Form 4137.” They explain when the tax applies: “If you received tips of $20 or more in any month and you didn’t report the full amount to your employer, you must pay the social security and Medicare or railroad retirement (RRTA) tax on the unreported tips.”
Noncash tips are treated differently: “Don’t include the value of any noncash tips, such as tickets or passes.” On how to figure the tax, the instructions say “To figure the social security and Medicare tax, use Form 4137.” The related Form 1040 line is covered on the page about unreported tip income, and the Form W-2 box that reports tips your employer knows about is explained on the page about box 7 social security tips.
Line 6: uncollected tax on wages
The caption for line 6 reads “Uncollected social security and Medicare tax on wages. Attach Form 8919”. The instructions say “Enter the total of any taxes from Form 8919.” They describe who uses the form: “If you are an employee who received wages from an employer who didn’t withhold social security and Medicare tax from your wages, use Form 8919 to figure your share of the unreported tax.”
There is one more direction on line 6: “Include on line 6 the amount from line 13 of Form 8919.” The instructions also tell you where a different Form 8919 amount goes: “Form 1040 or 1040-SR, line 1g”. That line is covered on the page about wages from Form 8919.
Line 7: the total
The caption for line 7 reads “Total additional social security and Medicare tax. Add lines 5 and 6”. Line 7 is the only one of the three that is a sum of other lines.
Where the number comes from
Line 5 comes from a completed Form 4137 and line 6 comes from a completed Form 8919. Neither number is worked out on Schedule 2 itself. The instructions say for line 5 “If you owe RRTA tax, contact your employer.” and then “Your employer will figure and collect the RRTA tax.”
Where it goes next
Line 7 is one of the lines added on line 21. The caption reads “Add lines 4, 7 through 16, 18, and 19. These are your total other taxes.” and then “Enter here and on Form 1040 or 1040-SR, line 23”. The whole schedule is on the Schedule 2 (Form 1040) page, the total on Form 1040 is on the lines 22, 23 and 24 page, and the return itself is on the Form 1040 page.
Edition and line numbers
This page reads the 2025 Schedule 2 (Form 1040) and the 2025 Form 1040 instructions, the current files irs.gov served on 2026-10-17. They are the files for the tax year 2025 return, filed in 2026. The schedule says “Attach to Form 1040, 1040-SR, or 1040-NR.” Its line instructions are part of the Form 1040 instructions, under the heading “Instructions for Schedule 2”. Check the tax year printed on the schedule you are filling in and use the line numbers on that year’s schedule, because a different year’s schedule can number or word its lines differently.
Common mistakes
- Leaving out unreported tips because the employer never saw them. The instructions say “you must pay the social security and Medicare or railroad retirement (RRTA) tax on the unreported tips.”
- Counting the value of tickets or passes received as tips. The instructions say “Don’t include the value of any noncash tips, such as tickets or passes.”
- Entering the wrong Form 8919 amount on line 6. The instructions say “Include on line 6 the amount from line 13 of Form 8919.”
Related: unreported tip income, wages from Form 8919, box 7 social security tips, and Form 1040.
Sources
- Instructions for Form 1040 and Form 1040-SR (2025): https://www.irs.gov/pub/irs-pdf/i1040gi.pdf
- Schedule 2 (Form 1040), Additional Taxes (2025): https://www.irs.gov/pub/irs-pdf/f1040s2.pdf
Read from the IRS documents linked above on October 17, 2026. General information, not tax advice. Your own facts decide the outcome, and a preparer, the account provider or the IRS is the right place to confirm anything consequential.